/*
 * 
 *                This source code is part of
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 *          GROningen MAchine for Chemical Simulations
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 *                        VERSION 3.2.0
 * Written by David van der Spoel, Erik Lindahl, Berk Hess, and others.
 * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
 * Copyright (c) 2001-2004, The GROMACS development team,
 * check out http://www.gromacs.org for more information.

 * This program is free software; you can redistribute it and/or
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#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <math.h>
#include "sysstuff.h"
#include "statutil.h"
#include "string.h"
#include "copyrite.h"
#include "smalloc.h"
#include "typedefs.h"
#include "confio.h"
#include "futil.h"
#include "macros.h"
#include "vec.h"
#include "index.h"
#include "gmx_fatal.h"
#include "gmx_ana.h"

int gmx_genpr(int argc,char *argv[])
{
  const char *desc[] = {
    "[TT]genrestr[tt] produces an include file for a topology containing",
    "a list of atom numbers and three force constants for the",
    "X, Y and Z direction. A single isotropic force constant may",
    "be given on the command line instead of three components.[PAR]",
    "WARNING: position restraints only work for the one molecule at a time.",
    "Position restraints are interactions within molecules, therefore",
    "they should be included within the correct [TT][ moleculetype ][tt]",
    "block in the topology. Since the atom numbers in every moleculetype",
    "in the topology start at 1 and the numbers in the input file for",
    "genpr number consecutively from 1, genpr will only produce a useful",
    "file for the first molecule.[PAR]",
    "The [TT]-of[tt] option produces an index file that can be used for",
    "freezing atoms. In this case, the input file must be a [TT].pdb[tt] file.[PAR]",
    "With the [TT]-disre[tt] option, half a matrix of distance restraints",
    "is generated instead of position restraints. With this matrix, that",
    "one typically would apply to C-alpha atoms in a protein, one can",
    "maintain the overall conformation of a protein without tieing it to",
    "a specific position (as with position restraints)."
  };
  static rvec    fc={1000.0,1000.0,1000.0};
  static real    freeze_level = 0.0;
  static real    disre_dist = 0.1;
  static real    disre_frac = 0.0;
  static real    disre_up2  = 1.0;
  static gmx_bool    bDisre=FALSE;
  static gmx_bool    bConstr=FALSE;
  static real    cutoff = -1.0;
	
  t_pargs pa[] = {
    { "-fc", FALSE, etRVEC, {fc}, 
      "force constants (kJ mol-1 nm-2)" },
    { "-freeze", FALSE, etREAL, {&freeze_level},
      "if the [TT]-of[tt] option or this one is given an index file will be written containing atom numbers of all atoms that have a B-factor less than the level given here" },
    { "-disre", FALSE, etBOOL, {&bDisre},
      "Generate a distance restraint matrix for all the atoms in index" },
    { "-disre_dist", FALSE, etREAL, {&disre_dist},
      "Distance range around the actual distance for generating distance restraints" },
    { "-disre_frac", FALSE, etREAL, {&disre_frac},
      "Fraction of distance to be used as interval rather than a fixed distance. If the fraction of the distance that you specify here is less than the distance given in the previous option, that one is used instead." },
    { "-disre_up2", FALSE, etREAL, {&disre_up2},
      "Distance between upper bound for distance restraints, and the distance at which the force becomes constant (see manual)" },
    { "-cutoff", FALSE, etREAL, {&cutoff},
      "Only generate distance restraints for atoms pairs within cutoff (nm)" },
    { "-constr", FALSE, etBOOL, {&bConstr},
      "Generate a constraint matrix rather than distance restraints. Constraints of type 2 will be generated that do generate exclusions." }
  };
#define npargs asize(pa)

  output_env_t oenv;
  t_atoms      *atoms=NULL;
  int          i,j,k;
  FILE         *out;
  int          igrp;
  real         d,dd,lo,hi;
  atom_id      *ind_grp;
  const char   *xfn,*nfn;
  char         *gn_grp;
  char         title[STRLEN];
  matrix       box;
  gmx_bool         bFreeze;
  rvec         dx,*x=NULL,*v=NULL;
  
  t_filenm fnm[] = {
    { efSTX, "-f",  NULL,    ffREAD },
    { efNDX, "-n",  NULL,    ffOPTRD },
    { efITP, "-o",  "posre", ffWRITE },
    { efNDX, "-of", "freeze",    ffOPTWR }
  };
#define NFILE asize(fnm)
  
  CopyRight(stderr,argv[0]);
  parse_common_args(&argc,argv,0,NFILE,fnm,npargs,pa,
		    asize(desc),desc,0,NULL,&oenv);
  
  bFreeze = opt2bSet("-of",NFILE,fnm) || opt2parg_bSet("-freeze",asize(pa),pa);
  bDisre  = bDisre || opt2parg_bSet("-disre_dist",npargs,pa);
  xfn     = opt2fn_null("-f",NFILE,fnm);
  nfn     = opt2fn_null("-n",NFILE,fnm);
  
  if (( nfn == NULL ) && ( xfn == NULL))
    gmx_fatal(FARGS,"no index file and no structure file suplied");
      
  if ((disre_frac < 0) || (disre_frac >= 1))
    gmx_fatal(FARGS,"disre_frac should be between 0 and 1");
  if (disre_dist < 0)
    gmx_fatal(FARGS,"disre_dist should be >= 0");
    
  if (xfn != NULL) {
    snew(atoms,1);
    get_stx_coordnum(xfn,&(atoms->nr));
    init_t_atoms(atoms,atoms->nr,TRUE);
    snew(x,atoms->nr);
    snew(v,atoms->nr);
    fprintf(stderr,"\nReading structure file\n");
    read_stx_conf(xfn,title,atoms,x,v,NULL,box);
  }
  
  if (bFreeze) {
    if (atoms && atoms->pdbinfo) 
      gmx_fatal(FARGS,"No B-factors in input file %s, use a pdb file next time.",
		xfn);
    
    out=opt2FILE("-of",NFILE,fnm,"w");
    fprintf(out,"[ freeze ]\n");
    for(i=0; (i<atoms->nr); i++) {
      if (atoms->pdbinfo[i].bfac <= freeze_level)
	fprintf(out,"%d\n",i+1);
    }
    ffclose(out);
  }
  else if ((bDisre || bConstr) && x) {
    printf("Select group to generate %s matrix from\n",
	   bConstr ? "constraint" : "distance restraint");
    get_index(atoms,nfn,1,&igrp,&ind_grp,&gn_grp);
    
    out=ftp2FILE(efITP,NFILE,fnm,"w");
    if (bConstr) {
      fprintf(out,"; constraints for %s of %s\n\n",gn_grp,title);
      fprintf(out,"[ constraints ]\n");
      fprintf(out,";%4s %5s %1s %10s\n","i","j","tp","dist");
    }
    else {
      fprintf(out,"; distance restraints for %s of %s\n\n",gn_grp,title);
      fprintf(out,"[ distance_restraints ]\n");
      fprintf(out,";%4s %5s %1s %5s %10s %10s %10s %10s %10s\n","i","j","?",
	      "label","funct","lo","up1","up2","weight");
    }
    for(i=k=0; i<igrp; i++) 
      for(j=i+1; j<igrp; j++,k++) {
	rvec_sub(x[ind_grp[i]],x[ind_grp[j]],dx);
	d = norm(dx);
	if (bConstr) 
	  fprintf(out,"%5d %5d %1d %10g\n",ind_grp[i]+1,ind_grp[j]+1,2,d);
	else {
	  if (cutoff < 0 || d < cutoff)
	  {
	    if (disre_frac > 0) 
	      dd = min(disre_dist,disre_frac*d);
	    else 
	      dd = disre_dist;
	    lo = max(0,d-dd);
	    hi = d+dd;
	    fprintf(out,"%5d %5d %1d %5d %10d %10g %10g %10g %10g\n",
		  ind_grp[i]+1,ind_grp[j]+1,1,k,1,
		  lo,hi,hi+1,1.0);
		}
	}
      }
    ffclose(out);
  }
  else {
    printf("Select group to position restrain\n");
    get_index(atoms,nfn,1,&igrp,&ind_grp,&gn_grp);
    
    out=ftp2FILE(efITP,NFILE,fnm,"w");
    fprintf(out,"; position restraints for %s of %s\n\n",gn_grp,title);
    fprintf(out,"[ position_restraints ]\n");
    fprintf(out,";%3s %5s %9s %10s %10s\n","i","funct","fcx","fcy","fcz");
    for(i=0; i<igrp; i++) 
      fprintf(out,"%4d %4d %10g %10g %10g\n",
	      ind_grp[i]+1,1,fc[XX],fc[YY],fc[ZZ]);
    ffclose(out);
  }
  if (xfn) {
    sfree(x);
    sfree(v);
  }  
  
  thanx(stderr);
 
  return 0;
}
